Monday, July 11, 2011

It is not just the lamps

When I began to read Brilliant: The Evolution of Artificial Light by Jane Brox, I was first prompted to consider the various technologies that have been used to light our homes and environment, from campfires to oil lamps to kerosene/mantle lamps to the electric filament bulb to fluorescents and LEDs. And what is next? Thinking about these things, and the continuing quest to produce more light and less heat, was behind this post of a couple days ago.

Ms Brox's book does indeed outline the progress of technologies used to create light, but I realized there is much more involved. There are three basic stages of light production, and each has been supported by a particular infrastructure, without which the light-producing device itself is of comparatively little use.

First, consider the technology of oil lamps, which are basically bowls with a wick and some melted or meltable oily substance. During the thousands (millions?) of years that this technology prevailed, there were the parallel technologies of oil/fat production and rendering, of producing the wicks, of passing the fire from place to place, and of starting the fire if yours has gone out and no near neighbor has any. This last was usually accomplished using a twirled hardwood rod, a dimple or hole in a piece of pine or other softwood, and some tinder.

When more volatile fuels such as light whale oil, kerosene and later coal gas came into use, primarily in Europe and America, there was a parallel development of chemical knowledge. Thus, while a technology for distributing fuels grew until it culminated in the neighborhood gas house and the piping systems that brought gaslight to homes and street corners, strikable matches and flint/steel strikers were also developed to make it easier to light one's lamps.

Finally, although the first incandescent electric light was energized in 1802 by Humphrey Davy, it took another 77 years of experimentation by many, including Edison's technicians, for a practical lamp to be produced. We give Edison credit for the bulb, but forget that his greater accomplishment was the infrastructure that made the bulb practical. The batteries of the day could only energize one of his bulbs for a short time, perhaps a few hours. Keeping that first bulb lit for fourteen hours until its glass envelope cracked was no mean feat, requiring the swapping of batteries in relays.

Thomas Edison envisioned a system of dynamos and underground, shielded wiring that would take care of the needs of a neighborhood at a time. His preference (almost a mania) for DC rather than AC current eventually led to his system being eclipsed by an AC infrastructure developed by George Westinghouse, based on Edison's but with the addition of transforming equipment so that power sent over a longer distance could be boosted to a higher voltage, reducing resistive losses in the wiring.

One characteristic of each successive infrastructure system has been increasing fragility. Thus, a few late chapters in the book cover the great blackout of 1965 and subsequent blackout events, and the efforts that are still being made to make "the grid" ever more robust and reliable. To meet the needs of the later 21st Century in America and Europe, at the very least, new trunk lines and newer switching equipment needs to be set up. It won't be cheap, but not doing it will eventually be hugely more costly. China, India and other major developing countries in Asia and Africa are watching our progress, so they can get their infrastructure right the first time.

With many business places lit entirely by fluorescent light, lighting consumes less than 8% of our energy budget. With many middle class homes using more and more CFL lamps, and a switch to LED's just beginning, this amount will decrease even more. But our use of light is the most visible manifestation of our electrical society. As we learn to make more light while using less energy to produce it, we also need to improve the efficiency of all our uses of energy.

I am reminded of something I learned forty years ago. AC power has this characteristic, that its use is less efficient if the voltage and current get out of phase. "Inductive" loads, such as electric motors, cause current to lag the voltage. "Capacitive" loads, and there are no simple examples, cause the current to lead instead. There are nearly no large electricity consuming devices that are capacitive, meaning that most industry operates with lagging current and its inherent inefficiencies. As it turns out, a type of electric motor called a synchronous motor acts as a large capacitive load. I don't understand the physics of it, so I can't explain why. Anyway, the primary market for large synchronous motors is major industrial plants that install them and keep them running just to balance the phase of their electricity, which significantly reduces their electric bill! I wonder if this would work at the house level. If I look at the transformers on the power poles up the street, I can see that some are accompanied by large capacitors, almost the size of the transformers, that the power company has installed to keep their own system in balance. Maybe there is a way to add a large capacitor or a synchronous motor in parallel with my furnace fan (the largest motor in the house). Don't hold your breath, but I do plan to look into this. Haven't given the matter any thought since 1970 until today!

The last chapter of the book is devoted to the loss of dark skies as we have gone to more and more street and exterior lighting. Not only is it inefficient, there is growing concern that it doesn't do as much as we thought to reduce crime. Perhaps just a little light is better than too much, while still being better than none at all. On my last visit to Japan, while my father-in-law was still living, I was told that he had installed most of the neighborhood's walkway lights. They were a series of single-tube fluorescent fixtures, and while they were nowhere near as bright as the lighting in my neighborhood, they were quite adequate for finding one's way around after dark. It was also easier to see the stars in the sky, which I much enjoy. His lights are probably very close to the amount of light we genuinely need, and a lot more economical than the way most American cities are lighted at present. Thanks to the author of Brilliant for such a thought-provoking book!